Open source HR software promises something no subscription HRIS can: no per-employee fees, full control over your data and the freedom to change the code. For the right organisation, that is a real advantage. For the wrong one, it means a sensitive system full of salaries, addresses and medical notes running on a server nobody is quite responsible for.
This guide compares five self-hosted HR systems, explains what their licences actually allow, and sets out the hidden costs so you can decide whether open source fits your team. We describe each project from its own website and code repository, checked in November 2026. We have not run production deployments of these systems.
What "open source" means for HR software
Many products call themselves open source. The test is the licence. The Open Source Initiative's Open Source Definition requires, among other things, that a licence "shall not restrict any party from selling or giving away the software" and "must not restrict anyone from making use of the program in a specific field of endeavor."
In practice, HR projects fall into three groups:
- Open source: licences such as GPL, LGPL or AGPL. You can run, study, modify and share the software. Copyleft licences (GPL, AGPL) require you to share your changes under the same licence if you distribute the software, and AGPL extends that to software offered over a network.
- Open core: a free open source edition plus paid features or modules under a commercial licence. Odoo is the best-known example.
- Source-available: the code is public but the licence restricts use. IceHrm's repository, covered below, falls here.
For an organisation running HR software internally, any of these may be fine. The licence matters most if you plan to host the system for clients, resell it or build a product on it.
The five options at a glance
| Project | Licence | Core modules | Paid hosting | Best for |
|---|---|---|---|---|
| OrangeHRM Starter | GPL-3.0 | Employee records, leave, reporting | Paid Advanced edition | Established, simple core HR |
| Frappe HR | GPL-3.0 | HR and payroll, leave, attendance, expenses | Frappe Cloud from $5/month | Payroll needs and ERPNext users |
| Horilla | LGPL-2.1 | Nine modules incl. recruitment, payroll, performance | Managed cloud $7/user/month | Broad modules on a modern stack |
| Odoo Community | LGPLv3 | Employees, recruitment, time off | Odoo Enterprise (licensed) | Businesses wanting HR inside an ERP |
| IceHrm | Elastic License 2.0 (source-available) | Leave, attendance, payroll, recruitment | IceHrm Cloud, IceHrmPro | Teams fine with a restricted licence |
OrangeHRM Starter
OrangeHRM is the longest-established project here. Its website describes Starter as "completely free and open-source HR software" for employee management, leave tracking and reporting, with an upgrade path to the paid Advanced edition, which adds modules such as recruitment, performance management and payroll integration. The GitHub repository is licensed under GPL-3.0, uses PHP and MySQL with a web installer and a REST API, and has around 1,200 stars.
- Strengths: maturity, a large user base, community forums, and a commercial company behind it if you later want support.
- Trade-offs: the free edition is deliberately limited; recruitment, performance and payroll sit in the paid edition. Repository activity is slower than the newer projects here.
- Best for: small and mid-sized organisations that want a stable, simple employee database and leave system.
Frappe HR
Frappe HR describes itself as a "100% open-source HR & Payroll product". It covers configurable pay structures and payroll with integrated accounting, employee loans, leave policies and encashment, mobile check-ins and roster management, and expense claims and advances. It integrates with ERPNext, the open source ERP from the same company. The GitHub repository is licensed under GPL-3.0 and is the most active project here, with around 9,000 stars and commits in the past week.
Its pricing page is frank about costs: self-hosting is free to licence but needs an estimated $40 a month for a server plus email, security and backup services, and several hours of setup and monthly maintenance. Managed hosting on Frappe Cloud starts at $5 a month for a single site on shared servers.
- Strengths: the only project here with substantial built-in payroll, plus an active community and a cheap managed option.
- Trade-offs: payroll rules need configuring for your country, and statutory filings remain your responsibility. The Frappe framework has its own learning curve.
- Best for: organisations already on ERPNext, and teams that want payroll and HR in one open source system.
Horilla
Horilla is an open source HRMS from Cybrosys Technologies, built on Django. Every plan includes nine modules: employees, recruitment, onboarding, attendance, leave, payroll, performance, assets and helpdesk. Self-hosting is "free forever if you run it", with a Docker install. A managed cloud plan costs $7 per user per month with the first 30 days free and includes updates, daily encrypted backups and a 99.9% uptime commitment; an enterprise plan adds single sign-on and implementation support. The GitHub repository is licensed under LGPL-2.1 and is actively maintained, with around 1,500 stars.
- Strengths: the broadest set of modules in a free edition, including recruitment and performance, on a modern Python stack.
- Trade-offs: a younger project with a smaller community than OrangeHRM or Frappe; check the depth of payroll for your country.
- Best for: small and mid-sized organisations that want recruitment-to-performance coverage without per-user fees.
Odoo Community
Odoo is an open core business suite. Its source code is published under the GNU Lesser General Public License, version 3 for the Community edition, while Enterprise is commercially licensed. According to Odoo's editions comparison, the Community edition includes the Employees, Recruitment and Time Off apps, while Payroll, Appraisals and Referrals are Enterprise-only.
- Strengths: HR inside a full ERP, alongside accounting, inventory, projects and timesheets, with a very large ecosystem of developers and partners.
- Trade-offs: core HR features you might expect, payroll and appraisals, require the paid edition, so a pure Community deployment is limited to records, recruitment and leave.
- Best for: businesses that already run, or plan to run, Odoo for operations and want basic HR in the same system.
IceHrm
IceHrm's website covers leave, attendance, payroll, recruitment, performance reviews, training and reporting, sold as IceHrm Cloud (managed hosting with a 14-day trial) or IceHrmPro (self-hosted with all extensions, an annual licence priced by team size). The code is public on GitHub, but its licence file is the Elastic License 2.0. Elastic's licence text says you "may not provide the software to third parties as a hosted or managed service" and may not circumvent licence key functionality.
- Strengths: a wide feature set and a clear commercial path.
- Trade-offs: source-available rather than open source; fine for internal use, but you cannot host it for clients.
- Best for: organisations comfortable with a restricted licence that want IceHrm's features with the option to self-host.
The real cost of self-hosting
The licence is free. Running HR software is not.
Infrastructure. A small server, backups, monitoring and email delivery. Frappe estimates around $40 a month for a basic self-hosted setup, which is a reasonable benchmark for the others.
Security. HR systems hold some of the most sensitive data an organisation has. Someone must apply security updates promptly, enforce strong authentication, encrypt backups and restrict access. A neglected HR server is a serious breach risk.
Upgrades. Major versions can change data structures and break customisations. Budget time for each upgrade, and test on a copy first.
Support. Community forums are helpful but not accountable. If payroll fails on payday, who fixes it? Most projects sell paid support or managed hosting for this reason.
Adoption. SHRM found that on average only 62% of employees actively use the HR technology their organisation implements. Open source projects vary widely in interface quality and mobile apps; test with real employees, not just HR.
When open source HR software makes sense
Open source is a good fit when:
- you have in-house technical skills or an IT partner who will own the system;
- data residency or control matters, for example in the public sector, NGOs or regulated industries;
- per-employee subscription fees are hard to justify, such as for large hourly or seasonal workforces;
- you need custom workflows that commercial HRIS vendors will not build.
It is a poor fit when:
- no one will own security and upgrades;
- you need a fully managed payroll service that files taxes for you;
- you need vendor accountability, service levels and certifications such as SOC 2 that procurement or clients demand.
SHRM research found that 30% of HR leaders regret their most recent HR technology purchase. Open source does not remove that risk; it moves it from the contract to your own team.
How to evaluate an open source HR project
1. Check the licence file, not the marketing. Confirm the licence in the repository and what it allows for your use case.
2. Check activity. Look at recent commits, releases and how quickly issues get answers. A project that has not been updated for months is a security risk.
3. Test core workflows. Run a pilot with your real leave policies, approval chains and, if relevant, payroll rules.
4. Plan the hosting. Decide between self-hosting and the project's managed cloud. Managed hosting from the maintainers is often the best of both worlds: open source code, someone else's pager.
5. Plan the exit. Make sure you can export employee records, documents and history in standard formats.
Our HRIS selection workbook gives you a structured way to score requirements across open source and commercial options alike.
Open source vs commercial HRIS
| Open source (self-hosted) | Commercial HRIS (SaaS) | |
|---|---|---|
| Licence cost | None | Per employee per month |
| Hosting and security | Your responsibility | Vendor's responsibility |
| Customisation | Unlimited, if you have developers | Within the vendor's settings |
| Payroll and tax filing | Configure and file yourself | Often fully managed |
| Support | Community or paid add-on | Included, with service levels |
| Data control | Full | Depends on the vendor's contract |
For a fuller view of commercial options, see our HRIS software comparison and our ultimate guide to HRIS systems. If you only need a free plan rather than self-hosted software, our guide to free HR software covers hosted free tiers.
Frequently asked questions
What is the best open source HR software?
It depends on what you need. Frappe HR is strongest on payroll and has the most active community. Horilla offers the broadest free modules, including recruitment and performance. OrangeHRM Starter is the most established choice for simple core HR.
Is open source HR software really free?
The licence is free, but running it is not. Expect costs for a server, backups and security, plus staff time for setup, updates and support. Managed hosting from the maintainers, such as Horilla at $7 per user per month or Frappe Cloud from $5 a month, is an alternative.
Is Odoo HR free?
Odoo Community, under LGPLv3, includes the Employees, Recruitment and Time Off apps. Payroll, Appraisals and Referrals are part of the paid Enterprise edition.
Is IceHrm open source?
Its code is public, but the repository's licence is the Elastic License 2.0, which restricts offering the software as a hosted service. That makes it source-available rather than open source in the OSI sense.
Is open source HR software secure?
It can be, if it is kept updated, hosted securely, backed up and access-controlled. The code being public is not the risk; an unmaintained installation is.